Early human decidual cells exhibit NK activity against the K562 cell line but not against first trimester trophoblast

The susceptibility of cultured first trimester human trophoblast cells to lysis by NK cells has been studied. Trophoblast cells are resistant to lysis by NK cells from both peripheral blood and decidua. However, decidual cells extracted by enzymatic disaggregation do exhibit cytotoxicity against the NK-sensitive cell line K562. The relevance of these findings to successful implantation of the blastocyst is discussed.     

Prognosis for infants born at 23 to 28 weeks' gestation.

The survival and neurodevelopmental outcome of 356 extremely preterm infants born at 23 to 28 weeks'' gestation were reported by week of gestation. Their corrected 1 year survival improved from 7% at 23 weeks to 75% at 28 weeks. The overall incidence of impairment was 19% and of major disability 12%. Boys had a significantly lower normal survival than girls. Multiple births had a significantly lower survival and higher incidence of impairment than singleton births. Predictions of outcome were made before delivery, after resuscitation, and at 1 week to aid the development of guidelines on when perinatal intensive care is justified, whether obstetric intervention for fetal reasons is warranted, and what initial and ongoing prognoses to give to parents. Intensive care for progressively smaller and more immature infants, many of whom were previously considered non-viable, needs to be carefully monitored by every perinatal centre.     

The response of human decidual leukocytes to IL-2.

The phenotype of human decidual leukocytes, composed predominantly of CD3-CD16(-)-CD56bright cells, was examined after culture with IL-2 by immunofluorescence and flow cytometry. After IL-2 stimulation the phenotype became like that found on classical NK cells, with an increased proportion of cells expressing CD16. The IL-2R alpha was absent before and after IL-2 stimulation. However, the intermediate affinity receptor, IL-2R beta, was expressed by CD56bright decidual cells, but this receptor was downregulated after IL-2 stimulation. IL-2-induced proliferation of CD56+ decidual cells could be blocked using TU27, a monoclonal antibody to the IL-2R beta. These findings indicate activation of decidual leukocytes by IL-2 occurs through the IL-2R beta alone.     

A genetic library screen for signaling proteins that interact with phosphorylated T cell costimulatory receptors

In the past decade, the fundamental importance and therapeutic potential of costimulatory signals for lymphocyte activation have spurred a large amount of work in immunology, infection, cancer, autoimmune diseases, etc. However, the mechanisms behind T cell costimulation remain unclear, partly due to the lack of suitable techniques. There is an urgent need for functional genomic research to develop comprehensive approaches to direct identification of protein-protein interactions that are dependent on the posttranslational modification of one component of the complex, particularly in the field of T cell immunology. Using inducible costimulator (ICOS) as a model, we failed to find any proteins that associated with the cytoplasmic tail of ICOS by the yeast two-hybrid approach. Therefore, we have developed a new yeast three-hybrid system that facilitates the rapid screening of cDNA libraries to find signaling molecules that interact with phosphorylated T cell costimulatory receptors. We demonstrate the utility of this technique to detect the interaction between ICOS and the p85 regulatory subunit of phosphatidylinositol 3-kinase (PI3K). The p85 unit of PI3K is the only signaling molecule identified so far that interacts with ICOS. This system may be of great help in dissecting the mechanisms of T cell costimulation and could be applied to other receptors.     

A new class of 5-HT2B antagonists possesses favorable potency,selectivity, and rat pharmacokinetic properties

We have been exploring the potential of 5-HT_2B antagonists as a therapy for chronic heart failure. To assess the potential of this therapeutic approach, we sought compounds possessing the following attributes: (a) potent and selective antagonism of the 5-HT_2B receptor, (b) low impact of serum proteins on potency, and (c) desirable pharmacokinetic properties. This Letter describes our investigation of a biphenyl benzimidazole class of compounds that resulted in 5-HT_2B antagonists possessing the above attributes. Improving potency in a human serum albumin shift assay proved to be the most significant SAR discovery.     

Determination of oxytetracycline and its degradation products by high-performance liquid chromatography-tandem mass spectrometry in manure-containing anaerobic test systems

This paper describes the development of a HPLC-MS-MS (ESI) method with baseline separation of oxytetracycline, 4-epi-oxytetracycline, alpha-apo-oxytetracycline and beta-apo-oxytetracycline using an XTerra column and an MeOH-MilliQ-water (containing 8 mM formic acid) mobile phase. Limits of quantification for aqueous standards were in the range of 0.004 to 0.008 microM. The linear range tested was 0.003 to 0.5 microM and in one case up to 17 microM. An experiment simulating the degradation of oxytetracycline in manure was set up and free concentrations of the four antibiotics were determined during 6 months. Oxytetracycline (>0.02 microM) was observed up till 6 months after spiking. No important increase in free concentrations of the degradation products was observed.     

Thermostable malate synthase of<Emphasis Type="Italic"> Streptomyces thermovulgaris</Emphasis>

The gene, encoding malate synthase (MS), aceB, was cloned from the thermophilic bacterium Streptomyces thermovulgaris by homology-based PCR. The 1,626-bp cloned fragment encodes a protein consisting of 541 amino acids. S. thermovulgaris malate synthase (stMS) gene was over-expressed in Escherichia coli using a glutathione-S transferase (GST) fusion vector (pGEX-6P-1), purified by affinity chromatography, and subsequently cleaved from its GST fusion partner. The purified stMS was characterized and compared to a mesophilic malate synthase (scMS) from Streptomyces coelicolor. stMS exhibited higher temperature optima (40–60 °C) than those of scMS (28–37 °C). It was more thermostable and very resistant to the chemical denaturant urea. Amino acid sequence comparison of stMS with four mesophilic streptomycete MSs indicated that they share 70.9–91.4% amino acid identities, with stMS possessing slightly more charged residues (~31%) than its mesophilic counterparts (~28–29%). Seven charged residues (E85, R187, R209, H239, H364, R382 and K520) that were unique to stMS may be selectively and strategically placed to support its peculiar characteristics.